the government and opposition are blaming each other for the shutdown. whatever the truth, syria's regime is battling these men for its very survival. president assad's helicopters are being shot down. and even a mig jet was filmed tumbling from the sky. this rebel boasting that he's downed both a helicopter and a mig within 24 hours. these surface to air missiles have been looted from captured military bases. what do we first with it a voice can be heard asking. not everybody knows how this newfound firepower works. yet this islamist brigade near damascus now has one. while near aleppo an entirm air defense system seems to have fallen to the so-called daoud battalion which is affiliated however loosely with al qaeda. "these are assad's missiles," say the cameraman and "we have taken them." london and washington may have refused to arm these rebels. but armed they are like never before. >> suarez: and margaret warner takes the story from there. >> warner: for more on today's developments and what they mean for syria's president bashar al assad, i'm joine